Commit 4a2398d7 authored by Linus Walleij's avatar Linus Walleij
Browse files

gpio: sch311x: Use RMW to change direction 



Bit 0 in the config register obviously controls the direction
of the GPIO so instead of hammering 0x0/0x1 into that register,
use read-modify-write so that we can also alter the other bits
in the register.

Cc: Bruno Randolf <br1@einfach.org>
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
parent f9e03b0e

drivers/gpio/gpio-sch311x.c

+12 −10
Original line number Diff line number Diff line
@@ -23,10 +23,9 @@ 


#define DRV_NAME			"gpio-sch311x"



#define SCH311X_GPIO_CONF_OUT		0x00

#define SCH311X_GPIO_CONF_IN		0x01

#define SCH311X_GPIO_CONF_INVERT	0x02

#define SCH311X_GPIO_CONF_OPEN_DRAIN	0x80

#define SCH311X_GPIO_CONF_DIR		BIT(0)

#define SCH311X_GPIO_CONF_INVERT	BIT(1)

#define SCH311X_GPIO_CONF_OPEN_DRAIN	BIT(7)



#define SIO_CONFIG_KEY_ENTER		0x55

#define SIO_CONFIG_KEY_EXIT		0xaa
@@ -196,10 +195,12 @@ static void sch311x_gpio_set(struct gpio_chip *chip, unsigned offset, 
static int sch311x_gpio_direction_in(struct gpio_chip *chip, unsigned offset)

{

	struct sch311x_gpio_block *block = gpiochip_get_data(chip);

	unsigned char data;



	spin_lock(&block->lock);

	outb(SCH311X_GPIO_CONF_IN, block->runtime_reg +

	     block->config_regs[offset]);

	data = inb(block->runtime_reg + block->config_regs[offset]);

	data |= SCH311X_GPIO_CONF_DIR;

	outb(data, block->runtime_reg + block->config_regs[offset]);

	spin_unlock(&block->lock);



	return 0;
@@ -209,12 +210,13 @@ static int sch311x_gpio_direction_out(struct gpio_chip *chip, unsigned offset, 
				      int value)

{

	struct sch311x_gpio_block *block = gpiochip_get_data(chip);

	unsigned char data;



	spin_lock(&block->lock);



	outb(SCH311X_GPIO_CONF_OUT, block->runtime_reg +

	     block->config_regs[offset]);



	data = inb(block->runtime_reg + block->config_regs[offset]);

	data &= ~SCH311X_GPIO_CONF_DIR;

	outb(data, block->runtime_reg + block->config_regs[offset]);

	__sch311x_gpio_set(block, offset, value);



	spin_unlock(&block->lock);
@@ -230,7 +232,7 @@ static int sch311x_gpio_get_direction(struct gpio_chip *chip, unsigned offset) 
	data = inb(block->runtime_reg + block->config_regs[offset]);

	spin_unlock(&block->lock);



	return !!(data & SCH311X_GPIO_CONF_IN);

	return !!(data & SCH311X_GPIO_CONF_DIR);

}



static int sch311x_gpio_probe(struct platform_device *pdev)